Reed contact with ball-shaped armature



July 19, 1966 e. WESSEL 3,261,942

REED CONTACT WITH BALL-SHAPED ARMATURE Filed May 19, 1964 2 Sheets-Sheet1 July 19, 1966 s. WESSEL 3,261,942

REED CONTACT WITH BALD-SHAPED ARMA'IURE Filed May 19, 1964 2Sheets-Sheet 2 United. States Patent ternational Standard ElectricCorporation, New York,-

N.Y., a corporation of Delaware Filed May 19, 1964, Ser. No. 368,535 3Claims. (Cl. 200-87) The invention relates to a reed contact in whichthe freely movable armature within the reed contact tube is in the shapeof a ball. The ball is made from magnetic material and is held inposition under the influence of at least one permanent magnet.

Known electro-magnetic relays have an armature, preferably ball-shaped,freely movable in the working air gap of the relay. The ball armature isheld under the influence of at least one permanent magnet. The iron coreof this relay is made of two straight rods, preferably with roundprofile, which are arranged successively and which limit with theiropposite ends the working air gap. The permanent magnet or magnets aredesigned as fiat construction elements, preferably rectangularshaped,and arranged in parallel to the plane in which the rods are located.This known arrangement of reed contact relays with ball-shaped armatureis, however, very expensive and difiicult to produce.

The object of the invention is to provide a reed contact relay whichconsists of elements that are easily constructed. Another object is toprovide reed contacts which can be used as make-, break-, orswitch-over-contacts, depending on the wiring connected to the endsprotruding from the tube.

These reed-type contacts are of particularly small dimensions. Accordingto the invention, particular care has been taken so that a large part ofthe ball surface of the armature will be used for contact making. Thisis achieved, according to the invention, by the use of rodshapedcontacts which are bent hairpin shaped in both ends of the reed tube,the rod-shaped contacts are melted into the tube in the way known. Theopen ends of the hairpins are opposite each other within the tube andhold the ball-shaped armature between them. Their closed, bent ends arelocated outside the tube. After having been melted in, these ends areseparated in a way known, so that four electrically separated contactpoints are ob tained. The rods formed on either front side of the twocontacting points are in parallel in one plane.

According to an embodiment of the invention the contact rods locatedparallel and in one plane are staggered by 90 with respect to the othertwo contact rods.

According to a further embodiment of the invention, the free ends of thecontact rods within the tube, and located opposite each other, arechamfered in such a way that the surface obtained by the chamferingshows to the central axis of the tube.

According to a further embodiment of the invention the contact rod pairslocated within a plane are chamfered in a varying angle, so that theball-shaped armature will be set into a rotating motion during theswitching of the contacts, in order to use the entire ball surface forcontact making during the numerous switchings to be performed during itslife expectancy.

An advantage of the invention is that the reed has a small design andcan be used as a contact for push buttons or push button controlledsystems. A further advantage is that by using equal constructionelements within a reed contact, a suitable connection may be made withina circuit by connecting the lugs protruding from the tube in amake-contact, a break-contact, or a switchover-contact configuration.There is no necessity for additional tools for manufacturing in order toobtain contacts with varying functions. Furthermore, it is necessary tohave separate supply for each of the individual 3,261,942 Patented July19, 1966 contact types. Since the contact pins within the tube arechamfered in a different angle, the ball receives a rotative motionduring the switching process whereby in the course of the switchingprocesses during the contacts life expectancy the entire ball surface isused for contact making.

The invention will now in detail be explained with the aid of an exampleand the accompanying drawings in which:

FIG. 1 shows a reed contact according to the invention seen from theside in section and essentially enlarged,

FIG. 2 shows a contact according to FIG. 1 in perspective view, and

FIG. 3 shows a cross-section through the contact in FIG. 2, taken alongthe line AA.

FIG. 1 shows a reed armature tube marked with the FIGURE 1. For example,the reed tube may be made of glass into which on either front side 2 and3 respectively hair-pin-bent contact elements 4 and 5 are meltedin.Within the tube between these contact elements 4 and 5, is a ball-shapedarmature 6.

Outside the reed tube 1 a permanent magnet 7 will be slid in thelongitudinal direction of the reed tube in a way knonw. The permanentmagnet 7 may consist of a longitudinal or rectangular ferrite magnet orof an annular magnet which will be slid over the tube. After meltinginto the tube 1 at the corresponding front side 2 and 3, the contactingelements 4 and 5 will be separated along the lines BB. Thus, forexample, from the contact element 4 are made two electrically insulatedcontacting rods 4' and 4", and from the contact element 5 are made twoseparated contact elements 5 and 5".

The contact rods 5 and 5" of the contact element 5 are in parallel inone plane. The same applies for the contact rods 4' and 4" of thecontact element 4. Within the tube 1, however, these planes between themelting-in point 2 and the melting-in point 3 are vertically to eachother. The contact rods 4, 4", 5', and 5", are chamfered at their freeedges within the tube. The free edges slant in such a way that thesurface obtained by the chamfering, as for example shown at the points 8or 9, shows to the centre axis of the tube and in the longitudinaldirection of the tube 1. Besides, the chamfering is made in varyingangles as shown at the points 8 and 9. Hence, the contacting ends of therods 5' and 5" touch the ball armature in a manner such that the ball isput into a rotating motion during the switching process in order to usethe entire ball surface for contact-making during the life of the reedContact.

For a clear understanding, FIG. 2 shows the contact of FIG. 1 in aperspective view. As already described in FIG. 1, the contact elements 4and 5 will be separated at the points BB after melting-in. If, e.g., acircuit is only connected to both contact rods 4 and 4", the armature 6bridges these two contact rods at the position of the permanent magnet 7as shown in FIG. 2, thus obtaining a break-contact between the contactrods 4' and 4". If, on the other hand, the contact rods 5' and 5" arewired into the circuit, there is no connection between these contactrods when armature 6 is held by the flux of the permanent magnet 7 inthe position as shown in FIG. 2.

When the permanent magnet 7 is moved in the direction of the arrow,which can be either by a push botton operation or the like, the armature6 within the tube 1 will be moved also in direction of the arrow. Thismotion disconnects the break-contact between the contact rods 4 and 4"and provides a connection between the contact rods 5' and 5"(make-contact). If, for example, the contact rods 4" and 5" are soconnected outside the tube, the function of a switch-over contact isobtained without any change of the interior design of the contact.

By the favourable design of the reed contact, the contact can bealternately used as break-contact only, as make-contact only, asbreakand make-contact, or as a switch-over-contact.

FIG. 3 shows, without the ball-shaped armature 6, a cross-section takenalong the line AA of FIG. 2. In this representation, it is particularlyemphasized that, for example, the contact element rods 5' and 5" areparallel in one plane and are vertical to the plane formed by thecontact rods 4 and 4". The contact elements 4 and 5, and the ball-shapedarmature 6 consist of a material which is magnetizable and which has anexpansion coeflicient that is adapted to the glass. The contact elements4 and 5, and the ball-shaped armature 6 are surface-treated according toa suitable method in order to make a suitable electrical conductivity,particularly at the contact-making points.

While I have described above the principles of my invention inconnection with specific apparatus, it is to be clearly understood thatthis description is made only by way of example and not as a limitationto the scope of my invention as set forth in the objects thereof and inthe accompanying claims.

What I claim is:

1. A glass reed type contact assembly comprising an elongated glassenvelope having a pair of rods sealed into each end of the envelope,each of said rods being oriented to provide a pair of spaced parallelrods inside the envelope, the ends of said rods forming four separateelectrical contacts outside the envelope, a ball-shaped armature insidethe envelope positioned to roll between said four electrical contacts,and means comprising a permanent magnet outside said envelope to controlthe position of said ball armature wherein the contact ends of said rodsare chamfered to provide tangential surfaces for touching said ball whenit makes contact therewith, the contact ends of said rods beingchamfered at different angles to cause said ball armature to rotateduring the switching process.

2. The assembly of claim 1 wherein each of said pairs of rods form twocontacts which are side by side in one plane.

3. The assembly of claim 2 wherein the two contacts formed by said onepair of rods lie in a plane which is set at 90 with respect to the planeof the two contacts formed by the other pair of said rods.

References Cited by the Examiner UNITED STATES PATENTS 2,715,166 9/1955Fitch 20087 2,732,464 1/1956 Ohl 200--87 2,892,051 6/1959 Moore 2008l.92,980,776 4/1961 Ovshinsky 200-87 2,995,635 8/1961 Ovshinsky et a1 200873,059,074 10/1962 Dal Bianco et a1 20087 BERNARD A. GILHEANY, PrimaryExaminer.

B. DOBECK, Assistant Examiner.

1. A GLASS REED TYPE CONTACT ASSEMBLY COMPRISING AN ELONGATED GLASS ENVELOPE HAVING A PAIR OF RODS SEALED INTO EACH END OF THE ENVELOPE, EACH OF SAID RODS BEING ORIENTED TO PROVIDE A PAIR OF SPACED PARALLEL RODS INSIDE THE ENVELOPE, THE ENDS OF SAID RODS FORMING FOUR SEPARATE ELECTRICAL CONTACT OUTSIDE THE ENVELOPE, A BALL-SHAPE ARMATURE INSIDE THE ENVELOPE POSITIONED TO ROLL BETWEEN SAID FOUR ELECTRICAL CONTACTS, AND MEANS COMPRISING A PERMANENT MAGNET OUTSIDE SAID ENVELOPE TO CONTROL THE POSITION OF SAID BALL ARMATURE WHEREIN THE CONTACT ENDS OF SAID RODS ARE CHAMFERED TO PROVIDED TANGENITAL SURFACES FOR TOUCHING SAID BALL WHEN IT MAKES CONTACT THEREWITH, THE CONTACT ENDS OF SAID RODS BEING CHAMFERED AT DIFFERENT ANGLES TO CAUSE SAID BALL ARMATURE TO ROTATE DURING THE SWITCHING PROCESS. 